u_long

[MoNksBaNe_Agahnim]

I have seen this before as a reserved word, mainly in bnet bots...

example

Code Select Expand

u_long u_flags

What is u_long exactly defining the variable u_flags as?

[K]

I have seen this before as a reserved word, mainly in bnet bots...

example

Code Select Expand

u_long u_flags

What is u_long exactly defining the variable u_flags as?

probably

Code Select Expand


typedef unsigned long u_long;


[iago]

I would assume it's unsigned long.

[MoNksBaNe_Agahnim]

what exactly does unsigned/signed mean?

[Adron]

what exactly does unsigned/signed mean?

An unsigned 32-bit integer uses 32 bits to represent the amount. It can take any integer value from 0 to 4294967295.

A signed 32-bit integer uses 31 bits to represent the amount and 1 bit to represent the sign. It can take any integer value from -2147483648 to 2147483647.


Example; 3-bit integer:

The left-most bit is the sign in a signed integer, so all values where that bit is 1 are negative.

Code Select Expand


binary unsigned signed
000     0        0
001     1        1
010     2        2
011     3        3
100    4        -4
101    5        -3
110    6        -2
111    7        -1


[Maddox]

Signed integers are represented by two's complement. That is the inversion of the bits + 1.

For example

Code Select Expand

unsigned int a = 96;
printf("%d %d\n", a, ~a + 1);
Outputs: 96 -96

[MrRaza]

what does the '~' do?

[Yoni]

~ is bitwise NOT - it complements each bit in the parameter. (0 becomes 1, 1 becomes 0.)